Abstract: A system in a transport refrigeration unit (TRU) for driving a compressor and/or fan(s) of the TRU by a variable frequency drive (VFD) that is operable using AC power comprises the VFD operatively connected between the compressor and one or more ac power source such as an engine-generator assembly of the TRU and/or an electrical grid. The same VFD or a different VFD is also operatively connected between the AC power source and fan(s) associated with an evaporator, and a condenser of the TRU. The VFD is configured to be operated by the AC power sources. The VFD is operable to receive a 3-phase AC power ranging from 200 to 650 volts and 0.25 to 25 KW from at least one of the AC power source, convert the received 3-phase AC power to supply AC or DC power to a motor associated with the compressor and/or the fan(s).

Abstract: A cooling system for a variable frequency drive (VFD) of a transport refrigeration unit (TRU) is disclosed. The system comprises a conduit disposed within the vehicle and extending between a opening provided at a first predefined position on the outer body of the vehicle and the VFD being positioned at a second predefined position within the vehicle. The opening facilitates the inflow of ambient air within the conduit that carries the ambient air towards the VFD to enable cooling of the VFD. The system includes a grill cover adapted to be removably attached to the opening and/or the first end of the conduit, which allows entry of the ambient air within the conduit and restricts entry of outside objects and/or living organisms within the conduit.